Electrochromism means that under an applied electric field, characteristics of a material, such as reflectivity, transmittance and absorptivity, can be changed reversibly based on a magnitude and polarity of the electric field. An electrochromic structure is arranged on a surface of a glass to form an electrochromic glass, such that a light transmitting performance of the glass can be controlled by controlling an applied voltage.
According to a report of the US Green Building Committee, energy consumed by buildings accounts for nearly 40% of the totally consumed energy. Heat loss from windows with poor isolation performance accounts for 10% to 30% of heat loss of buildings in winter. In summer, light passing through windows and into a building increases energy required for indoor cooling. It is estimated that, in the US, energy loss caused by glass windows of buildings is worth about 20 billion dollars each year.
With the electrochromic glass, amount of transmitting light and glaring light through an electrochromic glass can be controlled, such that the amount of transmitting light through the glass and an amount of heat through the glass can be optimized to keep the indoor condition comfortable, thereby reducing energy consumed in maintaining a certain temperature inside the building. Therefore, with the rapid development of material technology, the electrochromic glasses are gradually applied to fields such as automotive anti-glare mirrors, automotive sunroofs, windows for high-speed trains, windows for aircrafts and glass-curtain wall in high-end buildings. Moreover, with the gradual reduction of a comprehensive energy using cost, the electrochromic glass can gradually replace Low-e glasses, such that the electrochromic glass is widely used in energy-saving and environmental-friendly smart buildings.
However, the electrochromic glass according to the conventional technology often leak light when the electrochromic glass changes color due to an applied voltage around the electrochromic glass.